Lettuce, Endive, and Escarole

Introduction

Lettuce (Lactuca sativa), endive and escarole (both Cichorium endivia) are members of the Asteraceae plant family, and all originated in the Mediterranean region. Their closest crop relatives are artichoke, chicory and sunflower. 

Lettuce grows best at cool temperatures, making spring and fall the major production seasons in New England. While endive and escarole are also cool-season crops, they are more tolerant of high temperatures than lettuce and therefore make a good substitute for lettuce during the warmer mid-summer weather. 

Types and Varieties

There are five common types of lettuce.  Crisphead or iceberg is commonly found in produce markets. The leaves are thin and crisp, often with curled or serrated edges, and the head should be firm. Butterhead or bibb lettuce has a loose-leafed head with green or red outer leaves and cream or yellow inner leaves. Butterhead type lettuce requires careful handling as it bruises and tears easily. For this reason, it is best suited to local market sales. Cos or romaine is an upright plant with the smooth outer leaves and whitish green inner leaves. Some think the leaves are crisper than other heading types. The fourth general type is variously named leaf lettuce, loose leaf or loose head. Lettuce of this type does not form a head and the leaves may be serrated, deeply lobed or crinkled. Leaf lettuce color varies from light green to red to green with red speckles, adding attractive color to salad mixes. The fifth type is “one-cut” lettuce. Several different proprietary lines of one-cut lettuces are sold through various seed distributors. This lettuce type has a high leaf count and narrow leaf attachment, so can be harvested easily as a whole head (by cutting at the base) or loose-leaf (by cutting just above the base). Unlike most leaf lettuces, one cut lettuces are usually transplanted, which allows for quicker bed turnover. One-cut lettuces can have variable leaf shapes (smooth, lobed, serrated), colors (green, red) and textures (tender/butter-like, crisp/romaine-like).

Endive and escarole encompass many diverse types. Escarole and Frisée are types of endive (Cichorium endivia), both of which form loose and leafy heads. Radicchio and Belgian endive are forms of chicory (Cichorium intybus) that form small, tight heads. Belgian endive is grown in two stages: during spring/summer, the seeds produce large dandelion-like leaves and a large taproot, similar to carrot. In the fall, the taproots are dug, and potted and placed in the dark. The new growth from the roots produces small tight heads called chicons, which are marketed. Italian (or "culinary") dandelions form long leaves that are usually bunched.

Lettuce, Endive and Escarole Varieties
Lettuce - Butterhead Lettuce - Crisphead
Adriana - DM, LMV Caretaker - TB
Buttercrunch - DM, LMV Crispino
Milagro - DM, LMV  
Skyphos (red) Lettuce - Leaf
  Bergam's Green
Lettuce - Romaine New Red Fire (red)
Coastal Star Starfighter - DM, HT
Green Forest Tropicana 
Sparx - DM Two Star
Winter Density Muir - DM, LMV
Rouge d'Hiver (red)  
  Belgian Endive
Endive Totem
Green Curled  
Salad King Radicchio
  Leonardo
Escarole Sirio
Full Heart Perseo
Resistant or tolerant to: DM: Downy Mildew; LMV: Lettuce Mosaic Virus; TB:Tipburn

Soil Fertility

In general, lettuce, endive and escarole have the same fertility, spacing and seeding requirements. Apply lime according to soil test results to maintain soil pH at 6.5-6.8 and maintain soil calcium levels.  Low soil calcium levels may increase the incidence of tip burn. Tipburn is a disorder that causes the margins of leaves to turn black and decay. It is of particular concern with iceberg and romaine types where tipburn on internal leaves may not be immediately obvious. Over-application of nitrogen on fertile soil can result in very rapid growth which can trigger tipburn.  Banding the preplant fertilizer at planting is preferable, but if not possible, then broadcast and incorporate the initial application. Less nitrogen fertilizer will be needed if legume sod was plowed down or if manure was applied (see Table 1 and Table 7).

PLANT NUTRIENT RECOMMENDATION ACCORDING TO SOIL TEST RESULTS FOR LETTUCE, ENDIVE, AND ESCAROLE
LETTUCE, ENDIVE, AND ESCAROLE NITROGEN (N) LBS PER ACRE PHOSPHORUS (P) LBS P2O5  PER ACRE  POTASSIUM (K) LBS K2O      PER ACRE
SOIL TEST RESULTS   VERY LOW LOW OPTIMUM ABOVE OPTIMUM VERY LOW LOW OPTIMUM ABOVE OPTIMUM
Broadcast and Incorporate 50-75 180 120 30-60 0-30 180 120 30-60 0
Sidedress 3-4 Weeks after Planting 30-50 0 0 0 0 0 0 0 0
TOTAL RECOMMENDED 80-125 180 120 30-60 0-30 180 120 30-60 0

Planting

Generally lettuce, endive, and escarole have the same spacing and seeding requirements. Final spacing on crisphead lettuce, endive, and escarole should be 12-18" between plants (67-100 plants per 100 feet of row) and 12-24" between rows. Other types of lettuce can be 10-16" apart (75-120 plants per 100 feet of row) in 10-18" rows. Spacings should allow good air movement around the plants to minimize disease development. Many growers raise lettuce, endive, and escarole on 4' wide, raised, 4" high beds with 3 to 4 rows per bed. Crop rotation within and between seasons is recommended for disease management. For direct seeding, 10 to 18 oz of seed are needed per acre (0.0625-0.125 oz per 100 feet of row).

Lettuce will germinate at soil temperatures of 32ºF, but the optimum and maximum soil temperature is 75ºF. Temperatures above 80ºF will inhibit seed germination and cause bolting in lettuce. Temperatures below 70ºF will promote bolting in endive and escarole. Lettuce seed requires light to germinate and so should be seeded to a shallow depth. 

For once-over harvesting, uniformity at harvest is essential. Producers for direct retail markets and CSA might prefer variable maturity. Precision seeding with modern planters and coated seed can enhance uniformity. Irrigation immediately after seeding also promotes uniform emergence.

Since lettuce matures quickly (40-50 days), and temperature affects days to harvest, plant several successions to get consistent production into the summer. 

Lettuce is often started from transplants, which can be planted all season, from mid-April to August 1. Some growers use floating row covers over beds with early transplants for earlier crops. Hardened transplants should be set out when they are 3-4 weeks old. Hardening is accomplished by withholding water and gradually reducing temperatures for 10 days before the planned transplant date. Use of a liquid starter fertilizer at transplanting time can reduce shock and provide immediately available nitrogen and phosphorus in cold soil. Use a dilute solution to avoid injury to roots. In hot summer conditions, starting transplants in the greenhouse or shade house provides better germination than in the field.

Field Culture 

Hot temperatures cause lettuces to develop a bitter flavor and promote bolting. White on black plastic mulch (white above, black below) can be used to cool soil temperatures and reduce development of bitterness and bolting. Shade cloth can also be used to reduce heat stress in lettuce. Choose heat-tolerant varieties for mid-season production. 

Harvest and Storage 

Head lettuces should be harvested when heads are well-formed and solid by cutting at the base. A few wrapper leaves should be left on each head to protect during packing. Leaf lettuces can be harvested by hand or mechanically; a single crop can be harvested multiple times.

Food safety issues from microbial contamination are often linked to leafy greens that are eaten raw. It is important to follow some basic practices that are in accord with the guidance outlined in the Food Safety section of this guide.

Lettuce, escarole, and endive are fragile and highly perishible. Heading lettuces, endive, and escarole are more easily stored than leaf lettuces. Cool to 32-34ºF as quickly as possible after harvest and store at 98-100% relative humidity. These crops are damaged by freezing temperatures (32ºF).

Disease Control

NOTE: For the disease control products listed below, one product trade name and formulation is provided for each active ingredient (common name) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases, there are other products available with the same active ingredient. Please see Table 25 and Fungicides and Bactericides Alphabetical Listing by Trade Name for more information on products with the same active ingredients.

The symbol OG   indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more detail.

Bottom Rot (Rhizoctonia solani)

Rotate crops with non-hosts. Do not plant into fields having significant undecomposed crop residues. Plant in well-drained sites and avoid over-irrigation. Cultivars with upright growth habits are less susceptible.

azoxystrobin (Quadris): 0.40 to 0.80  fl oz/1000 row feet; PHI 0d, REI 4h, Group 11. Apply in-furrow or as a banded application.

Bacillus amyloliquefaciens strain D747 (DoubleNickel LCOG): 0.12 to 1.0 lb/A as a soil drench; PHI 0d, REI 4 h, Group 44.

boscalid (Endura): 8.0 to 11.0 oz/A; PHI 14d, REI 12h, Group 7. Suppression only.

iprodione (Rovral 4 F): 1.5 to 2.0 pt/A; PHI 14d, REI 24h, Group 2. Lettuce only.  Direct application to soil and plant base.  Do not cultivate after application.

polyoxin D (OSO 5% SC): 3.75 to 13.0 fl oz/A; PHI 0d, REI 4h, Group 19.

Trichoderma asperellum, T. gamsii (Bio-tam 2.0OG): See label for in-furrow, drench, and broadcast rates; REI 1h, Group NC.

Gray Mold (Botrytis cinerea)

Avoid close planting and orient rows in the direction of prevailing winds. Do not plant in poorly drained areas. Plant on raised beds. Minimize damage to lettuce by cultural practices or other pathogens and pests. Avoid overhead irrigation. Do not plant where excessive plant residues are present. Transplanting mature plants results in more breakage. Romaine types are especially susceptible.

boscalid (Endura): 8.0 to 11.0 oz/A; PHI 14d, REI 12h, Group 7. Apply at seeding or transplant. A protective fungicide barrier is needed to maximize control.

cyprodinil plus fludioxonil (Switch 62.5 WG): 11.0 to 14.0 oz/A; PHI 0d, REI 12h, Groups 9 & 12. 

penthiopyrad (Fontelis): 14.0 to 24.0 fl oz/A; PHI 3d, REI 12h, Group 7.

polyoxin D (OSO 5% SC): 3.75 to 13.0 fl oz/A; PHI 0d, REI 4h, Group 19.

Ulocladium oudemansii (BotryStopOG): 2-4 lbs/A; REI 4h, Group not applicable. Begin application when conditions are conducive to disease development.

Downy Mildew (Bremia lactucae)

Lettuce downy mildew is favored by cool, rainy weather. Night temperatures of 43°F to 50°F and day temperatures of 55°F to 70°F with 100% humidity are ideal for disease development. As temperatures increase, the disease disappears. Plant resistant cultivars. Use irrigation practices that reduce leaf wetness and humidity. Protect greenhouse grown transplants with fungicides so that the disease is not introduced into the field.

acibenzolar-S-methyl (Actigard 50 WG): 0.75 to 1.0 oz/A; PHI 7d, REI 12h, Group 21. Apply preventively on a 7-10 day schedule. See label for details.

ametoctradin & dimethomorph (Zampro): 14.0 fl oz/A; PHI 0d, REI 12h, Groups 45 & 40.

azoxystrobin (Quadris): 12.0 to 15.5 fl oz/A; PHI 0d, REI 4h, Group 11. Proceed with caution with regard to tank mixes and adjuvants. Do not rotate with other Group 11 fungicides.

copper compound (Badge X2OG): 1.75 to 3.5 lb/A; PHI 0d, REI 48h, Group M1. Rate and REI vary with product.

copper hydroxide (Kocide 3000): 0.75 to 1.5 lb/A; PHI 0d, REI 48h, Group M1. Do not apply in a spray solution having a pH less than 6.5 or tank mix with Aliette. Injury may occur to sensitive lettuce cultivars.

cyazofamid (Ranman): 2.75 fl oz/A; PHI 0d, REI 12h, Group 21.

cymoxanil (Curzate 60 DF): 3.2 to 5.0 oz/A; PHI 3d (head) and PHI 1d (leafy), REI 12h, Group 27. Must be applied as tank mix with a protectant fungicide.

dimethomorph (Forum):  6 fl oz/A; PHI 0d, REI 12h, Group 40. Must be applied as tank mix with another fungicide with a different mode of action.

famoxadone & cymoxanil (Tanos): 8 to 10 oz/A; PHI 1d, REI 12h, Groups 11 & 27. Tank mix with appropriate contact fungicide with a different mode of action. Do not make more than one application before alternating to a fungicide with a different mode of action.

fenamidone (Reason 500 SC): 5.5 to 8.2 fl oz/A; PHI 2d, REI 12h, Group 11. Do not make more than one application before alternating to a fungicide with a different mode of action. Do not alternate with Quadris.

fluopicolide (Presidio): 3.0 to 4.0 fl oz/A; PHI 2d, REI 12h, Group 43. Must be tank mixed with a fungicide with a different mode of action.

fluxapyroxad & pyraclostrobin (Merivon): 8.0 to 11.0 fl oz/A. PHI 21d, REI 12h, Groups 7 & 11.

mancozeb (Dithane F45): 1.2 to 1.6 qt/A; PHI 10d (head) or PHI 14d (leaf), REI 24h, Group M3.

mancozeb plus copper hydroxide (ManKocide): 1.0 to 2.0 lb/A; PHI 10d, REI 48 h, Groups M3 & M1. 

mandipropamid (Revus): 8 fl oz/A; PHI 1d, REI 4h, Group 40. Addition of a spreading/penetrating adjuvant is recommended.

oxathiapiprolin (Orondis Ultra A): 2.0-4.8 fl.oz/A; PHI 0d, REI 4h, Group 49. Begin foliar application prior to disease development.

propamocarb HCl (Previcur Flex): 2.0 pt/A; PHI 2d, REI 12h, Group 28.

pyraclostrobin (Cabrio EG): 16.0 oz/A; PHI 0d, REI 12h, Group 11.

Drop, White Mold (Sclerotinia minor)

Do not plant seed contaminated with sclerotia (small black hardened fungal survival structures). Avoid planting into severely infested fields. Rotate with non-host crops like grasses. Avoid excessive nitrogen fertilization and irrigate in the morning or with sub-surface drip irrigation to provide dry soil. Deep plow after harvest to bury sclerotia. Soil sterilization with chemicals, steam, or heat (solarization) treatments can significantly reduce inoculum levels. Biofumigation with mustard crop may provide a suppressive effect.

boscalid (Endura): 8.0 to 11.0 oz/A; PHI 14d, REI 12h, Group 7. Apply at seeding or transplant. A protective fungicide barrier is needed to maximize control.

Coniothyrium minitans (Contans WGOG): Apply 1 to 4 lb/A in 20 to 50 gal water; REI 4h, Group NC. Spray on the soil surface and incorporate into the top 2" of soil. Fall application is best or 3 to 4 months before planting to allow for the biocontrol agent to infect the sclerotia of Sclerotinia.

cyprodinil plus fludioxonil (Switch 62.5 WG): 11.0 to 14.0 oz/A; PHI 0d, REI 12h, Groups 9 & 1.

fludioxonil (Cannonball WG): 7.0 oz/A; PHI 0d, REI 12h, Group 12.

fluxapyroxad & pyraclostrobin (Merivon): 8.0 to 11.0 fl oz/A. PHI 21d, REI 12h, Groups 7 & 11.  

iprodione (Rovral 4F): 1.5 to 2 pt/A; PHI 14d, REI 24h, Group 2. Lettuce only. Direct application to lower stems and branches and adjacent soil surface.  Do not cultivate after application.

penthiopyrad (Fontelis): 16.0 to 24.0 fl oz/A; PHI 3d, REI 12h, Group 7.

polyoxin D (OSO 5% SC): 3.75 to 13.0 fl oz/A; PHI 0d, REI 4h, Group 19.

Trichoderma asperellum, T. gamsii (Bio-tam 2.0OG): See label for in-furrow, drench, and broadcast rates; REI 4h, Group NC.

Ulocladium oudemansii (BotryStopOG): 2.0-4.0 lbs/A; REI 4h, Group not applicable. Begin application when conditions are conducive to disease development.

Seed Decay

Use treated seed. Do not use treated seed for food, feed or oil purposes.

mefenoxam (Apron XL): 0.085 to 0.64 fl oz/100 lb seed; REI 48h, Group 4. For Pythium damping-off protection.

fludioxonil (Maxim 4FS): 0.08 to 0.16 oz/100 lb seed; REI 12h, Group 12. For protection against seedborne and soilborne fungi. Does not control Pythium or Phytophthora.

thiram (Thiram SC): 8.0 fl oz/100 lb seed; REI 24h, Group M3.

Mosaic (Lettuce and Cucumber Mosaic Viruses)

Certified LMV- and CMV-free seed available. Plant certified disease-free seed away from old lettuce fields.

Yellows

Do not plant lettuce or other sensitive crops in fields or areas having a history of this disease. Control weeds in the Asteraceae family. Control leafhoppers, which carry the disease-causing organism (phytoplasma).

Insect Control

NOTES:  For the insecticides listed below, one product trade name and formulation is provided for each active ingredient (AI) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases, there are other products available with the same AI. Please see Table 26 and Insecticides Alphabetical Listing by Trade Name for more information on these insecticides.

The designation (Bee: L, M, or H) indicates a bee toxicity rating of low, moderate, or high. See the Protecting Honeybees and Native Pollinators section for more details.

The symbol * indicates a product is a restricted use pesticide. See Pesticide Safety and Use for more details.

The symbol OG   indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more details.

Aphids, Lettuce (Nasonovia ribisnigri)

The most common aphid present on lettuce is the lettuce aphid, of European origin, which overwinters on Ribes species including gooseberries and currants. Winged aphids that colonize lettuce are dark, while wingless females that reproduce on lettuce are pale yellow to green, sometimes reddish, with darker patches. Unlike other aphid species, they feed in the interior of the head, making them difficult to detect and to reach with insecticides. Scout plants at the seedling stage and before heads form. Check field margins, where infestations begin. If one planting becomes infested, use tillage to incorporate crop residue and prevent spread to later succession plantings. Potato aphid, green peach aphid or lettuce root aphid may also occur. See Potato for more information on potato aphid, and Pepper for more information on green peach aphid.

acephate (Orthene 97): 0.5 to 1 lb/A; PHI 21d, REI 24h, Bee: H, Group 1B. Green Peach Aphid only. For head lettuce (crisphead) only.

acetamiprid (Assail 30SG): 2 to 4 oz/A; PHI 7d, REI 12h, Bee: M, Group 4A.

afidopyropen (Versys): 1.5 fl oz/A; PHI 0d, REI 12h, Bee: L, Group 9D.

alpha-cypermethrin (Fastac* EC): 3.2 to 3.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

azadirachtin (Azatin OOG): 4 to 16 oz/A foliar or drench, 4 to 16 oz/100 gal in greenhouses. When using lower rates, combine with adjuvant for improved spray coverage and translaminar uptake; PHI 0d, REI 4h, Bee: L, Group UN.

Beauveria bassiana (Mycotrol ESOOG): 8 to 32 oz/A; PHI 0d, REI 4h, Bee: L, Group UN. Treat when populations are low and thoroughly cover foliage. Takes 7 to 10 days after the first spray to see control. Repeat applications may be needed.

bifenthrin (Brigade* 2EC): 2.1 to 6.4 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A. Head lettuce only.

Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 2 to 3 lb/A; PHI 0d, REI 4h, Bee: M, Group UN.

cyantraniliprole (Exirel): 13.5 to 20.5 oz/A; PHI 1d, REI 12h, Bee: H, Group 28. Green peach aphid only.

cyantraniliprole (Verimark): 6.75 to 13.5 oz/A; PHI 0d, REI 4h, Bee: H, Group 28. For soil applications at planting. For control of green peach and suppression of potato aphid only.

dimethoate (Dimethoate 4EC): 8 oz/A; PHI 14d for escarole types and leaf lettuce, REI 48h, Bee: H, Group 1B. Not for head lettuce.

dinotefuran (Safari 20SG): 0.16 to 0.25 oz/1,000 sq ft or 3.5 to 5.5 oz/100 gal or 7 to 11 oz/A; REI 12h, Bee: H, Group 4. Transplants only while in greenhouse. Not for field use.

dinotefuran (Venom): 1 to 3 oz/A foliar or 5 to 7.5 oz/A soil; PHI 7d foliar, PHI 21d soil, REI 12h, Bee: H, Group 4A. Soil application may be as a band during bedding, in-furrow at seeding, transplant or post-seeding drench, sidedress, or through drip. For green peach and potato aphid only.

flonicamid (Beleaf 50SG): 2 to 2.8 oz/A; PHI 0d, REI 12, Bee: L, Group 9C.

flupyradifurone (Sivanto): 7 to 10.5 oz/A for foliar application, 21 to 28 oz/A for soil application; PHI 1d foliar, PHI 21d soil, REI 4h, Bee: L, Group 4D.

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A. Suppression only.

imidacloprid (Admire Pro): 1.3 oz/A foliar, 4.4 to 10.5 oz/A soil; PHI 7d foliar, PHI 21d soil, REI 12h, Bee: H, Group 4A. For foliar applications, apply only to fully leafed-up canopies.

insecticidal soap (M-PedeOG): 1.25 to 2.5 oz/gal water; PHI 0d, REI 12h, Bee: L. Spray to wet all infested plant surfaces. May need to make repeated applications. For enhanced and residual control, apply with a companion labeled insecticide; for green peach aphid, must use companion insecticide.

malathion (Malathion 57 EC): 1.5 to 2 pt/A endive, 2 pt/A lettuce; PHI 7d for endive, PHI 14d for lettuce, REI 24h, Bee: H, Group 1B. Not for escarole.

methomyl (Lannate LV*): 1.5 to 3 pt/A; PHI 10d, REI 48h, Bee: H, Group 1A. For lettuce only.

petroleum oil (Suffoil XOG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L. Apply as needed. Lettuce only.

pymetrozine (Fulfill): 2.75 oz/A; PHI 0d, REI 12h, Bee: L, Group 9B. Translaminar. Apply when aphids first appear, before populations build up.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

sodium tetraborohydrate decahydrate (Prev-AM): 100 oz/100 gal; REI 12h, Bee: L, Group 25. Do not apply in midday sun or mix with copper, sulfur or oils. Lettuce only.

spirotetramat (Movento): 4 to 5 oz/A; PHI 3d, REI 24h, Bee: M, Group 23. Must be tank-mixed with a spray adjuvant with spreading and penetrating properties to maximize leaf uptake and sytemicity; don't use sticker adjuvants. Controls immature stages; may also reduce adult fertility.

sulfoxaflor (Closer SC): 1.5 to 2 oz/A; PHI 3d, REI 12h, Bee: H, Group 4C.

thiamethoxam (Actara): 1.5 to 3 oz/A; PHI 7d, REI 12h, Bee: H, Group 4A.

thiamethoxam (Platinum): 5 to 11 oz/A; PHI 30d, REI 12h, Bee: H, Group 4A. Systemic insecticide used as an in-furrow, banded, drench, or drip irrigation application to the seed/seedling root zone during or after planting/transplanting operations.

Aster Leafhopper (Macrosteles quadralineatis)

See Carrot and Parsnip section for more information on aster leafhopper and the yellows mycoplasm that it vectors.

acephate (Orthene 97): 0.5 to 1 lb/A; PHI 21d, REI 24h, Bee: H, Group 1B. Aster leafhopper. For head lettuce (crisphead) only.

alpha-cypermethrin (Fastac* EC): 2.2 to 3.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

beta-cyfluthrin (Baythroid* XL): 0.8 to 1.6 oz/A for potato leafhopper; 2.4 to 3.2 for other leafhoppers; PHI 0d, REI 12h, Bee: H, Group 3A.

bifenthrin (Brigade* 2EC): 2.1 to 6.4 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A. Head lettuce only.

carbaryl (Sevin XLR Plus): 0.5 to 1 qt/A; PHI 14d, REI 12h, Bee: H, Group 1A.

dimethoate (Dimethoate 4EC): 8 oz/A; PHI 14d for escarole types and leaf lettuce, REI 48h, Bee: H, Group 1B. Not for head lettuce.

dinotefuran (Venom): 1 to 3 oz/A foliar or 5 to 7.5 oz/A soil; PHI 7d foliar, PHI 21d soil, REI 12h, Bee: H, Group 4A. Soil application may be as a band during bedding, in-furrow at seeding, transplant or post-seeding drench, sidedress, or through drip.

flupyradifurone (Sivanto): 7 to 10.5 oz/A; PHI 1d, REI 4h, Bee: L, Group 4D.

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A.

imidacloprid (Admire Pro): 1.3 oz/A foliar, 4.4 to 10.5 oz/A soil; PHI 7d foliar, PHI 21d soil, REI 12h, Bee: H, Group 4A. For foliar applications, apply only to fully leafed-up canopies.

insecticidal soap (M-PedeOG): 1.25 to 5 oz/gal water; PHI 0d, REI 12h, Bee: L. Spray to wet all infested plant surfaces.

lambda-cyhalothrin (Warrior* II): 1.28 to 1.92 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A. Lettuce only.

malathion (Malathion 57 EC): 2 pt/A; PHI 14d, REI 24h, Bee: H, Group 1B. For lettuce only. 

methomyl (Lannate LV*): 1.5 to 3 pt/A; PHI 10d, REI 48h, Bee: H, Group 1A. For aster leafhopper on lettuce only.

permethrin (Pounce 25WP*): 3.2 to 12.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

petroleum oil (Suffoil XOG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L. Apply as needed.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

thiamethoxam (Actara): 1.5 to 3 oz/A; PHI 7d, REI 12h, Bee: H, Group 4A.

thiamethoxam (Platinum): 5 to 11 oz/A; PHI 30d, REI 12h, Bee: H, Group 4A. Systemic insecticide used as an in-furrow, banded, drench, or drip irrigation application to the seed/seedling root zone during or after planting/transplanting operations.

tolfenpyrad (Torac): 14 to 21 oz/A; PHI 1d, REI 12h, Bee: H, Group 21A.

zeta-cypermethrin (Mustang*): 2.4 to 4.3 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

Cabbage Looper (Trichoplusia ni)

An occasional pest of lettuce, especially in late season when migratory flights have brought high numbers of looper moths into New England. See Cabbage section for more information on cabbage looper.

acephate (Orthene 97): 1 lb/A; PHI 21d, REI 24h, Bee: H, Group 1B. For head lettuce (crisphead) only.

alpha-cypermethrin (Fastac* EC): 3.2 to 3.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

azazadirachtin (Azatin OOG): 4 to 16 oz/A foliar or drench, 4 to 16 oz/100 gal in greenhouses. When using lower rates, combine with adjuvant for improved spray coverage and translaminar uptake; PHI 0d, REI 4h, Bee: L, Group UN.

Bacillus thuringiensis aizawai (XenTariOG): 0.5 to 1.5 lb/A; PHI 0d, REI 4h, Bee: L, Group 11. Must be ingested; apply in evening before larvae are actively feeding. Adherence and weather-fastness will improve with use of an approved spreader-sticker. Use high rate at cool temperatures. For resistance management, may be rotated with Bt kurstaki products (Dipel).

Bacillus thuringiensis kurstaki (Dipel DFOG): 0.5 to 2 lb/A; PHI 0d, REI 4h, Bee: L, Group 11. Must be ingested; apply in evening before larvae are actively feeding. Adherence and weather-fastness will improve with use of an approved spreader-sticker. Use high rate at cool temperatures. For resistance management, may be rotated with Bt aizawai products (XenTari).

beta-cyfluthrin (Baythroid* XL): 1.6 to 2.4 oz/A; PHI 0d, REI 12h, Bee: H, Group 3A.

bifenthrin (Brigade* 2EC): 2.1 to 6.4 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A. Head lettuce only.

chlorantraniliprole (Coragen): 3.5 to 7.5 oz/A; PHI 1d, REI 4h, Bee: L, Group 28. May be applied to soil at planting, through drip chemigation and as a foliar spray. For soil applications, must be applied uniformly in the root zone.

Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 1 to 3 lb/A; PHI 0d, REI 4h, Bee: M, Group UN.

cyantraniliprole (Exirel): 10 to 17 oz/A; PHI 1d, REI 12h, Bee: H, Group 28.

cyantraniliprole (Verimark): 6.75 to 13.5 oz/A; PHI 0d, REI 4h, Bee: H, Group 28. For soil applications at planting.

cyclaniliprole (Harvanta): 10.9 to 16.4 fl oz/A; PHI 1d, REI 4h, Bee: H, Group 28.

emamectin benzoate (Proclaim*): 3.2 to 4.8 oz/A; PHI 7d, REI 12h, Bee: H, Group 6. Apply when larvae are first observed.

gamma-cyhalothrin (Declare*): 0.77 to 1.28 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A.

indoxacarb (Avaunt): 2.5 to 3.5 oz/A; PHI 3d, REI 12h, Bee: H, Group 22.

methomyl (Lannate LV*): 1.5 to 3 pt/A; PHI 10d, REI 48h, Bee: H, Group 1A. For lettuce only.

methoxyfenozide (Intrepid 2F): 4 to 10 oz/A; PHI 1d, REI 4h, Bee: L, Group 18. Use lower rates when plants are small or infestations are light.

permethrin (Pounce* 25WP): 3.2 to 12.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A. Not for escarole.

petroleum oil (Suffoil XOG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L. Apply as needed. Lettuce only.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

sodium tetraborohydrate decahydrate (Prev-AM): 50 oz/100 gal; REI 12h, Bee: L, Group 25. Do not apply in midday sun or mix with copper, sulfur or oils. Lettuce only.

spinetoram (Radiant SC): 5 to 10 oz/A; PHI 1d, REI 4h, Bee: M, Group 5.

spinosad (Entrust SCOG): 3 to 6 oz/A; PHI 1d, REI 4h, Bee: M, Group 5.

tebufenozide (Confirm 2F): 6 to 8 oz/A; PHI 7d, REI 4h, Bee: L, Group 18. Use low rate for early season applications to young, small plants. Use of an adjuvant is recommended.

zeta-cypermethrin (Mustang*): 3.4 to 4.3 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

Cutworms

Caterpillars hide under the soil surface adjacent to the plant stem during the day and feed on stems after dark. For best results, make application between midnight and dawn while cutworms are feeding aboveground. Synthetic pyrethroids (Group 3A) may work best during cool spring weather. See cutworms in the Pepper and Tomato (Outdoor) sections for more information on the black and variegated cutworms.

alpha-cypermethrin (Fastac* EC): 2.2 to 3.8 oz/A; PHI 1d, REI 12h, Bee:H, Group 3A.

Bacillus thuringiensis aizawai (XenTariOG): 0.5 to 1.5 lb/A; PHI 0d, REI 4h, Bee: L, Group 11. Must be ingested; apply in evening before larvae are actively feeding. Adherence and weather-fastness will improve with use of an approved spreader-sticker. Use high rate at cool temperatures. For resistance management, may be rotated with Bt kurstaki products (Dipel).

Bacillus thuringiensis kurstaki (Dipel DFOG): 0.5 to 1 lb/A; PHI 0d, REI 4h, Bee: L, Group 11. Must be ingested; apply in evening before larvae are actively feeding. Adherence and weather-fastness will improve with use of an approved spreader-sticker. Use high rate at cool temperatures. For resistance management, may be rotated with Bt aizawai products (XenTari).

beta-cyfluthrin (Baythoid* XL): 0.8 to 1.6 oz/A; PHI 0d, REI 12h, Bee: H, Group 3A.

bifenthrin (Brigade* 2EC): 2.1 to 6.4 oz/A; PHI 7d, REI 12h, Bee: H, Group 3A. Head lettuce only.p

Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 1 to 3 lb/A; PHI 0d, REI 4h, Bee: M, Group UN.

gamma-cyhalothrin (Declare*): 0.77 to 1.28 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A.

lambda-cyhalothrin (Warrior* II): 0.96 to 1.6 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A. Lettuce only.

methoxyfenozide (Intrepid 2F): 4 to 10 oz/A; PHI 1d, REI 4h, Bee: L, Group 18. Use lower rates when plants are small or infestations are light.

permethrin (Pounce* 25WP): 6.4 to 12.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

spinosad (SeduceOG): 20 to 44 lb/A or 0.5 to1 lb/1000 sq ft.; PHI 1d, REI 4 h, Bee: M, Group 5. Spread bait on soil around plants.

zeta-cypermethrin (Mustang*): 2.4 to 4.3 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

Tarnished Plant Bug (Lygus lineolaris)

The tarnished plant bug (TPB) is a small (1/4”) bronze-colored insect with a triangular marking on its back. TPB adults are highly mobile. The immature, or nymph stage is smaller and bright green, resembling an aphid, but much more active. Adults overwinter in weeds and crop residue and become active in early spring, laying eggs in plant tissue. Young tissue such as flower buds, immature fruit, and emerging leaves are preferred feeding sites compared to mature fruit, stems or leaves. There are 2 to 3 generations per year. There are both native and imported predators and parasites of TPB. The sucking injury from adults and nymphs can cause dieback of the growing tip, death and drop of buds or flowers, brown scars on leaf ribs, and distorted or stunted growth of leaves, pods, seeds or fruit. TPB injury in lettuce includes piercing of leaf ribs, which leaves a brown scar; this is especially noticeable on romaine. The range of vegetable and fruit crops affected by TPB is great; field crops such as alfalfa and many weeds are also favored hosts. In this guide, celery, lettuce, bean and eggplant list TPB as a pest, but these are not the only crops that could be affected. In vegetables, TPB is generally not a seriously damaging pest unless the vegetation surrounding crop fields is serving as a source of large populations, and the crop offers more succulent feeding than the surrounding fields. Avoid planting lettuce near abandoned, weedy fields or alfalfa crops.  While alfalfa may serve as a trap crop, mowing alfalfa may cause TPB to leave mowed fields for nearby vegetables causing TPB populations to increase. In strawberries, white sticky traps are used to detect adults and shaking flower trusses is used to detect nymphs; check small fruit alerts for TPB spring activity. Scout plants for signs of injury and for TPB adults or nymphs, especially in favorite, hidden feeding sites. Sweep nets can be used in crops that are not damaged by sweeping. Insecticides are warranted if damage is increasing and the crop stage is such that significant crop injury can be prevented.

beta-cyfluthrin (Baythroid* XL): 2.4 to 3.2 oz/A; PHI 0d, REI 12h, Bee: H, Group 3A.

carbaryl (Sevin XLR Plus): 1 to 2 qt/A; PHI 14d, REI 12h, Bee: H, Group 1A.

flonicamid (Beleaf 50SG): 2 to 2.8 oz/A; PHI 0d, REI 12, Bee: L, Group 9C.

gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A.

insecticidal soap (M-PedeOG): 1.25 to 5 oz/gal water; PHI 0d, REI 12h, Bee: L. Spray to wet all infested plant surfaces.

lambda-cyhalothrin (Warrior* II): 1.28 to 1.92 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A. For lettuce only.

petroleum oil (Suffoil XOG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L. Apply as needed.

pyrethrin (PyGanic EC5.0OG): 4.5 to 17 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.

Slugs

Damage appears as shredded foliage. Look for silvery slime trails on leaves or turn over soil clods or debris to find slugs during daylight hours. Grow plants away from moist, shaded habitats, use clean cultivation, control weeds, hand pick/crush slugs or scatter baits on the ground near infested plants. See the Cabbage section for more information on slugs.

iron phosphate (Sluggo: Snail and Slug BaitOG): 20 to 44 lb/A; PHI 0d, REI 0h, Bee: L, Group 9B. Apply around perimeter, scatter around base of plants, or band down rows. Apply to moist soil in the evening.

metaldehyde (Deadline Bullets): 20 to 40 lb/A; REI 12h, Bee: L. Soil surface treatment broadcast pre-planting, or band treatment between rows after formation of edible parts. Apply to moist soil in the evening. Do not apply directly to or contaminate edible portions of plants.

Weed Control

NOTE:  For the herbicides listed below, one product trade name and formulation is provided for each active ingredient along with preharvest interval (PHI), restricted entry interval (REI), resistance management group number, and example of rates and special instructions. In many cases, there are other products available with the same active ingredient. However, not all products with the same active ingredient are registered for use in a crop. Always check the product label to be sure that the crop is listed before using. 

See section on Soil Fumigation Outdoors in the Disease Management section. Proper use of Vapam can provide control of most weed species.

Stale Seedbed

See Stale Seedbed Technique in the Weed Management section. In place of herbicides, flaming can also be used.

carfentrazone (Aim EC): REI 12h, Group 14. Apply up to 2 oz/A per application, and do not exceed a total of 6.1 oz/ per season. 

glyphosate (Roundup Power Max): REI 12h, Group 9.

paraquat (Gramoxone SL 2.0*): restricted use. REI 12h, Group 22. Use 2 – 4 pts/A.  Preplant or stale seedbed application. May be fatal if swallowed or inhaled. Applicators must complete an EPA-approved paraquat training listed on the following website https://www.epa.gov/pesticide-worker-safety/paraquat-dichloride-training.... The training must be completed a minimum of every three years.

pelargonic acid (Scythe): PHI 1d, REI 12h, Group 17. Use a 3 -10% solution (3 to 10 gallons per 100 gallons).

Herbicides Used Preemergence, before weeds germinate

bensulide (Prefar 4E): REI 12h, Group 8. Apply 5 to 6 qt/A. Can be preplant incorporated by shallow cultivation (1-2”) or applied preemergence and incorporated by irrigation within 36 hours of application. Mainly annual grass control, and should be supplemented with cultivation or another registered herbicide for broadleaf control. See label for rotation restrictions.

pronamide (Kerb SC): PHI 25 to 55d (based on rate used), 24 hr REI, Group 3. Must be applied prior to weed emergence.  Can be applied either pre-plant, post-plant, or postemergence to head or leaf lettuce, endive, escarole or radicchio greens in banded, bed-topped or broadcast applications.  It is necessary to move Kerb into the root zone of germinating weeds to provide effective control (by overhead sprinkler irrigation, by rainfall, or by shallow mechanical incorporation).  See label for rotation restrictions.

The rate required is dependent on soil texture, target weeds, and method of irrigation/incorporation. Read label carefully to select the proper rate based on your farm conditions.  Apply 2.5 to 5.0 pts/A per acre for head lettuce, endive, escarole, and radicchio greens.  Apply 1.25 to 5.0 pts/A per acre for leaf lettuce.  Up to two applications are permitted and must be separated by at least 10 days.  Total product applied must not exceed 5.0 pts/A.

trifluralin (Treflan HFP): REI 12h, Group 3. Endive and escarole only. Apply 1 to 2 pts/A as a soil-incorporated treatment in spring or early summer prior to planting. Rate based on soil texture and crop, see label for details. Must be incorporated into the top 2 to 3 inches of the final seedbed within 24 hours of application.  Disc twice after spraying for satisfactory incorporation. See label for info on incorporation recommendations based on different equipment and single pass incorporation.

Herbicides Used Postemergence, after weeds germinate

carfentrazone (Aim EC): REI 12h, Group 14.  Aim is a burndown herbicide and will injure any foliage it comes into contact with. Apply Aim to row middles of emerged crops with hooded sprayers to control emerged weeds, including crops grown on mulch or plastic.  Prevent any spray from contacting the crop, or injury will occur.  For best results, make application to actively growing weeds up to 4 inches tall and rosettes less than 3 inches across. Good coverage is essential for good control.  Apply up to 2 oz/A per application, and do not exceed a total of 6.1 oz/ per season. 

clethodim (Select Max)PHI 14d, 24hr REI, Group 1.  Will control grass weeds only. Apply to actively growing grasses.  See label for rate selection.  Multiple applications permitted of 9 to 16 oz/A per application, minimum 14 days between applications, not to exceed 64 oz/A per year.  Add 0.25% v:v nonionic surfactant (1 qt per 100 gal of spray).  Can also be used as a spot-spray by mixing 1/3-2/3% (0.44 to 0.85 oz per gallon) Select Max and 0.25% v:v nonionic surfactant (0.33 oz per gallon).  Spray to wet, but do not allow runoff of spray solution.

fluazifop (Fusilade DX): PHI 14d, REI 12h, Group 1.  For lettuce (leaf and head).  For grass weed control only. Apply to actively growing grasses (see product label for susceptible stage). Apply up to 24 oz/A per application. Can use up to 2 applications per year, allow for minimum 14-days between applications (max 48 oz/A per year).  Add either crop oil concentrate (0.5-1%, 0.5-1 gallon per 100 gallons of spray) or nonionic surfactant (0.25-0.5%, 1-2 qt per 100 gal of spray).

pelargonic acid (Scythe): PHI 1d, REI 12h, Group 17. Use a 3 -10% solution (3 to 10 gallons per 100 gallons). Use a 3 to 5% solution for annual weeds, a 5 to 7% solution for biennial and perennial weeds, and 7 to 10% solution for maximum burndown. Delivery rate for boom applications should be 75 to 200 gals of spray solution per acre; complete coverage of weed foliage is essential. Use a DIRECTED/ SHIELDED SPRAY; contact with crop will cause injury. For hand-held equipment, spray to completely wet all weed foliage but not to the point of runoff. Repeat applications as necessary. Tank mixes are allowed with this product. See label for complete details.

sethoxydim (Poast): PHI 30d head lettuce; PHI 15d for leaf lettuce, escarole, and endive, REI 12h, Group 1.  Controls grass weeds only.  Apply to actively growing grasses (see product label for susceptible stage).  Maximum 1.5 pt/A per application, minimum 14-days between applications.  Do not exceed 3 pt/A per year. Use with crop oil concentrate (2.0 pt/A) or methylated seed oil (1.5 pt/A).  Note that crop oil can cause injury under hot and humid conditions.  Can also be used as a spot-spray by mixing 1-1.5% (1.3 to 1.9 oz per gallon) Poast and 1% v:v crop oil concentrate (1.3 oz per gallon).  Spray to wet, but do not allow runoff of spray solution.

Physiological Disorders

Tip Burn

This is a physiological condition caused by the plant's inability to obtain sufficient calcium due to rapid plant growth, excessive fertilization rates, or uneven water availability. Resistant varieties are available. Avoid excess fertilization. Provide consistent irrigation via drip irrigation systems. Foliar calcium supplements may have some benefit.